International Potato Center

About: International Potato Center is a facility organization based out in Lima, Peru. It is known for research contribution in the topics: Population & Phytophthora infestans. The organization has 1036 authors who have published 1460 publications receiving 47183 citations.

Detection of bacterial wilt infection caused by Ralstonia solanacearum in potato ( Solanum tuberosum L.) through multifractal analysis applied to remotely sensed data

Abstract: Potato bacterial wilt, caused by the bacterium Ralstonia solanacearum race 3 biovar 2 (R3bv2), affects potato production in several regions in the world. The disease becomes visually detectable when extensive damage to the crop has already occurred. Two greenhouse experiments were conducted to test the capability of a remote sensing diagnostic method supported by multispectral and multifractal analyses of the light reflectance signal, to detect physiological and morphological changes in plants caused by the infection. The analysis was carried out using the Wavelet Transform Modulus Maxima (WTMM) combined with the Multifractal (MF) analysis to assess the variability of high-resolution temporal and spatial signals and the conservative properties of the processes across temporal and spatial scales. The multispectral signal, enhanced by multifractal analysis, detected both symptomatic and latently infected plants, matching the results of ELISA laboratory assessment in 100 and 82%, respectively. Although the multispectral method provided no earlier detection than the visual assessment on symptomatic plants, the former was able to detect asymptomatic latent infection, showing a great potential as a monitoring tool for the control of bacterial wilt in potato crops. Applied to precision agriculture, this capability of the remote sensing diagnostic methodology would provide a more efficient control of the disease through an early and full spatial assessment of the health status of the crop and the prevention of spreading the disease.

Makers and Users of Geomorphological Maps

Abstract: In the last 60 years, geomorphology has been recognised as an important field serving several other professions. At the same time there are still limited resources spent on either national or regional geomorphological mapping programmes compared to geological, soil, land cover mapping programmes. From the maker's point of view, interesting exceptions in Europe are, for instance, the German, Austrian, Dutch, Spanish, and Italian national geomorphological mapping programmes. From the user's point of view, one of the strongest supporters of applied geomorphological mapping is the British Engineering Geological Community that has understood the added value of engineering geomorphological mapping and the economic savings in project developments when this practice is in place. In this scenario, it is the private sector – for instance the insurance sector – and the ecological community that have the highest potential of upscaling geomorphological mapping efforts. We review existing national geomorphological mapping efforts and further develop the needs of geomorphological mapping in natural hazards zonation and landscape planning.

Sequences of defective RNAs associated with potato yellow vein virus

Abstract: E. Eliasco1, I. C. Livieratos1,2, G. Müller3, M. Guzman4, L. F. Salazar3, and R. H. A. Coutts1 1Department of Biological Sciences, Imperial College London, Sir Alexander Fleming Building, London, U.K. 2Mediterranean Agronomic Institute of Chania (MAICH), Alsyllion Agrokepion, Chania, Crete, Greece 3The International Potato Center, Lima, Peru 4Faculty of Agronomy, Biotechnology Institute, Universidad Nacional de Colombia, Sede, Bogota, Colombia

Transforming impact assessment: beginning the quiet revolution of institutional learning and change

Abstract: SUMMARY Scores of assessments of the impacts of agricultural research have been carried out over the years. However, few appear to have been used to improve decision making and the effectiveness of research programmes. The Institutional Learning and Change (ILAC) Initiative emerged within the Consultative Group on International Agricultural Research (CGIAR), with the goal of strengthening learning from experience and using lessons to improve pro-poor innovation. It is testing approaches for expanding the contributions of impact assessment and evaluation to learning, decision making and improvement.

Anatomical root responses of rice to combined phosphorus and water stress – relations to tolerance and breeding opportunities

Abstract: Drought and low P availability are major limitations for rainfed rice (Oryza spp.) production. Root anatomy plays a key role in resource acquisition and tolerance to P and water limitations. Root anatomical responses of three contrasting rice varieties to combinations of different levels of P (deficient to non-limiting) and water availability (water stress to submergence) were evaluated in two pot trials. P availability was the dominant growth-limiting factor, but anatomical root responses to water availability were more prominent than responses to P availability. Cortical cell file number and number of xylem vessels decreased as a response to water stress, but stele and xylem diameter increased. Low P availability induced thinner xylem vessels and a thinner stele. Drought tolerance related to an overall thicker root stele, thicker xylem vessels and a larger water conductance. Some root traits were observed to be more responsive to water and P availability, whereas other traits were more robust to these environmental factors but highly determined by variety. The observed genotypic variation in root anatomy provides opportunities for trait-based breeding. The plasticity of several traits to multiple environmental factors highlights the need for strategic trait selection or breeding adapted to specific target environments.